Jenny Morris on the Hygiene Hypothesis – ‘Are we too clean or not clean enough?’

In the first of our blogs from Jenny Morris, our Strategic Advisor and former Principal Policy Offer for the CIEH, she takes a look at the re-emergence of the ‘Hygiene Hypothesis’ and the implications this could have on food safety and hygiene.

I’ve been to a couple of interesting conferences recently that have started me thinking about why people choose to cut corners when it comes to managing food safety. If we can develop a good understanding of this we should be able to improve compliance standards, something of great value in food safety, and in essence the aim that many of us work towards.

A great deal of work has been done on behavioural insights, which shows there are many reasons why people break rules. For instance, an individual might decide that the effort required was too great, that the rules were unnecessary or harmful and that no-one would notice. There are multiple factors involved here but it’s the issue of beliefs based on misunderstandings or myths, such as ‘it’s harmful’, in relation to the ‘Hygiene Hypothesis’ that I am going to tackle now.

The re-emergence of the ‘Hygiene Hypothesis’

I’m a person who tends to practice what I preach when it comes to food safety and hygiene. I believe it’s essential to maintain high standards and that much harm can result if we drop our guard. But it’s not uncommon to hear, or read comments such as ‘We’ve gone over the top with hygiene and its fuelling the increase in allergies’. And more worryingly that ‘a bit of dirt is a good thing’.

So, what’s behind this dangerous thinking?  Well it appears to be the re-emergence of the ‘Hygiene Hypothesis’, which argues that the rise in illnesses such as asthma, hay fever, eczema and food allergies is linked to reduced microbial exposure, because of measures to protect against infectious diseases e.g. hygiene controls such as cleaning and hand washing.

It is true that allergic illnesses are increasing and, whilst we have made progress in reducing foodborne illness, it’s estimated that there are still some 500,000 cases a year, most of which are avoidable. Just imagine how the numbers might skyrocket if we don’t maintain high hygiene standards.

The problem is that there is a ‘germ of truth’ (please forgive the pun) in the argument, so it can’t be dismissed entirely as ‘fake news’.

If we go back to hygiene basics we know that whilst we live in a world full of microbes, most are harmless or essential. Some, however, need to be tightly controlled – pathogens and spoilage organisms.

The need for a diverse microbiome

It’s becoming clearer that due to modern living we have lost contact with some of the microbial ‘old friends’, which are vital to our health. We need a diverse microbiome (our own collection of microbes e.g. in the gut and nose or on the skin) and we don’t always achieve this. It’s thought this is due to modern lifestyles e.g. lack of diversity in diet (limiting exposure to essential bacteria) and over use of antibiotics.

Studies show that an unhealthy microbiome, is linked with many chronic diseases such as irritable bowel syndrome, colorectal cancer, clostridium difficile infection, allergic illnesses and obesity.

So, there is a great deal to be gained from having a diverse microbiome but unlike the thinking of the ‘Hygiene Hypothesis’, we won’t achieve this by random exposure to dirt. Probiotics and faecal microbiome transplants may be some of the answers.

Setting the record straight

Let’s set the record straight and clear up any misunderstanding that might affect hygiene compliance. There are no benefits in cutting corners in food safety, only risks that pathogens may survive, grow and cause harm. We need to maintain high standards of environmental and food hygiene. And this will become ever more important as antimicrobial resistance increases, as without effective antibiotics foodborne illness will become much more than ‘just a touch of D and V’.

Reducing allergic illness is important but we won’t achieve it by being ‘dirtier’. Taking actions as outlined in previous Shield Safety blogs Time to get nuts about allergens and 7 handy tips to manage allergens are much more effective and safer ways of reducing the risk of allergic food reactions and complying with the law.

Do you need some extra support in managing food safety and hygiene? The UK’s largest team of Environmental Health professionals are here to help. Simply drop us an email at or call 020 3740 3744 to find out more.

The information contained in this blog article has been created for marketing purposes and is not official guidance and should not be used as a substitute for official Food Safety, Fire Safety and Health & Safety advice. Shield Safety take no responsibility if the information in the blog article is used to form part of a safety management system or used to form part of any legal or regulatory compliance for your business. For official guidance and to engage with Shield Safety services please do call our team on 020 3740 3744 or email

Sign up for our blog


Shield Safety Group

Food Safety

Latest insights

6 hours | 3 mins
Continuous Improvement: Why Trust Is The Bedrock Of Excellence In Hospitality

In the hospitality industry, nothing is static. New innovations are always emerging, customer expectations evolving, […]

Read post
3 weeks | 3 mins
From Risk to Re-assurance: 5 Tips For Transforming Your Business’ Allergy Policy

When you work in the hospitality industry, ensuring the safety of every guest is paramount […]

Read post
4 weeks | 2 mins
Essential Safety Tips for Managing Allergies

Allergies affect millions worldwide, impacting people of all ages and backgrounds. In the UK alone, […]

Read post

Keep in touch